greetings,
Im new and this seems like a dumb question, but I was wondering how do I attach wires into my Arduino's Pins (pin9 and GND) so they wont come out so easily? I dont want them to be permanent, but Im going to be using this to light LEDs in a helmet, and although, nothing will pull on them, I dont want them to pop out.
Putting jumper pins into header holes is not very reliable at all! The pins will fall out. If you are building this into a helmet, perhaps use a smaller Arduino like a Nano, without headers, that you can solder your wires into. If you are set on using jumpers and header holes, try putting a small blob of solder on the pin. Not a lot, but just enough to increase the friction so it doesn't slip out. Then fold the wire down, and tape it to the board.
A strip of pin headers will be much more firmly held than individual pins, this is why stacking
shields is mechanically pretty robust.
Try a Nano with one of these:
Or a similar screw shield / proto shield for the uno.